Chapter 11 Blood Mosby items and derived items

Chapter 11 Blood Mosby items and derived items © 2012 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 1

BLOOD COMPOSITION (Table 11 -1) Blood plasma Definition—blood minus its cells Ø Composition—water containing many dissolved substances (e. g. , nutrients, salts, and hormones) Ø Amount of blood—varies with size and sex; 4 to 6 L about average; about 7% to 9% of body weight Ø Mosby items and derived items © 2012 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 2

Mosby items and derived items © 2012 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 3

BLOOD COMPOSITION (cont. ) Formed elements Ø Types • RBCs (erythrocytes) • WBCs (leukocytes) Granular leukocytes—neutrophils, eosinophils, and basophils Nongranular leukocytes—lymphocytes and monocytes • Platelets, or thrombocytes Ø Count • RBCs— 4. 5 to 5 million per mm 3 of blood • WBCs— 5000 to 10, 000 per mm 3 of blood • Platelets— 300, 000 per mm 3 of blood Ø Formation—red bone marrow (myeloid tissue) forms all blood cells except some lymphocytes and monocytes, which are formed by lymphatic tissue in the lymph nodes, thymus, and spleen Mosby items and derived items © 2012 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 4

BLOOD COMPOSITION (cont. ) RBCs Structure—disk-shaped, without nuclei Ø Functions—transport oxygen and carbon dioxide Ø Anemia—inability of blood to carry adequate oxygen to tissues; caused, for example, by: Ø • Inadequate RBC numbers • Deficiency of hemoglobin • Pernicious anemia—deficiency of vitamin B 12 Polycythemia—abnormally high RBC count Ø Hematocrit test—medical test in which a centrifuge is used to separate whole blood into formed elements and liquid fraction (Figure 11 -3) Ø • • • Buffy coat is WBC and platelet fraction Normal RBC level is about 45% Erroneous test result can be caused by dehydration Mosby items and derived items © 2012 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 5

Mosby items and derived items © 2012 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 6

BLOOD COMPOSITION (cont. ) WBCs (leukocytes) General function—defense Ø WBC count Ø • Differential WBC count reveals proportions of each type of WBC • Leukopenia—abnormally low WBC count • Leukocytosis—abnormally high WBC count Ø Ø Neutrophils and monocytes carry out phagocytosis Lymphocytes produce antibodies (B-lymphocytes) or directly attack foreign cells (T-lymphocytes) Eosinophils protect against parasitic irritants and allergies Basophils produce heparin, which inhibits clotting Mosby items and derived items © 2012 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 7

BLOOD COMPOSITION (cont. ) WBC disorders Ø Leukemia—cancer • Elevated WBC count • Cells do not function properly Platelets and blood clotting (Figure 11 -6) Platelets play an essential role in blood clotting Ø Blot clot formation Ø • Clotting factors released at the injury site produce prothrombin activator • Prothrombin activator and calcium convert prothrombin to thrombin • Thrombin reacts with fibrinogen and triggers formation of fibrin, which traps RBCs to form a clot Mosby items and derived items © 2012 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 8

Mosby items and derived items © 2012 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 9

BLOOD TYPES ABO system (Figure 11 -7) Antigen—substance that can activate immune system Ø Antibody—substance made by body in response to stimulation by an antigen Ø Blood types Ø • Type A blood—type A self-antigens in RBCs; anti-B type • • • antibodies in plasma Type B blood—type B self-antigens in RBCs; anti-A type antibodies in plasma Type AB blood—type A and type B self-antigens in RBCs; no anti-A or anti-B antibodies in plasma Type O blood—no type A or type B self-antigens in RBCs; both anti-A and anti-B antibodies in plasma Mosby items and derived items © 2012 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 10

Mosby items and derived items © 2012 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 11

BLOOD TYPES (cont. ) Rh system Rh-positive blood—Rh factor antigen present in RBCs Ø Rh-negative blood—no Rh factor present in RBCs; no anti-Rh antibodies present naturally in plasma; anti-Rh antibodies, however, appear in the plasma of Rh-negative persons if Rh-positive RBCs have been introduced into their bodies Ø Mosby items and derived items © 2012 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 12

BLOOD TYPES (cont. ) Universal donor and universal recipient blood Type O Rh negative—universal donor blood Ø Type AB Rh positive—universal recipient blood Ø Hemolytic disease of the newborn or Erythroblastosis fetalis—may occur when Rh-negative mother carries a second Rh-positive fetus; caused by mother’s Rh antibodies reacting with fetus's Rh-positive cells Mosby items and derived items © 2012 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 13